title: Pressure and electrokinetic injections for on-line sample stacking neutral analytes in microemulsion electrokinetic chromatography with salt-containing matrixes.
abstract: An on-line technique for pressure and electrokinetic injections of long sample plugs with simultaneous stacking of neutral analytes (notoginsenoside R(1), ginsenoside Rg(1), ginsenoside Rf, ginsenoside Rh(1), ginsenoside Rd, ginsenoside Rg3) in microemulsion electrokinetic chromatography is presented. The effects of salt concentration, sample plug length, organic modification of the sample matrix, oil phase and SDS concentration on stacking efficiency were examined in order to optimize the two injection methods. In microemulsion electrokinetic chromatography, the effect of the type of oil and SDS content on stacking mechanism is often sophisticated. This study had demonstrated that the oil type and SDS content in microemulsion indeed markedly altered the affinity of microemulsion with analytes. Finally, in comparison with the electrokinetic injection method, the most apparent disadvantages of the pressure injection method were the relatively high LOD and poor reproducibility.
authors.affiliation: Key Laboratory of Modern Chinese Medicines (China Pharmaceutical University), Ministry of Education, Nanjing, PR China.
authors.forename: Jun
authors.initials: J
authors.lastname: Cao
authors.forename: Lian-Wen
authors.initials: LW
authors.lastname: Qi
authors.forename: Jun
authors.initials: J
authors.lastname: Chen
authors.forename: Ping
authors.initials: P
authors.lastname: Li
mesh_terms: D020374:Chromatography, Micellar Electrokinetic Capillary; D004655:Emulsions; D036145:Ginsenosides / Q000032:analysis*; D008832:Microchemistry; D009994:Osmolar Concentration; D011312:Pressure; D015203:Reproducibility of Results; D012492:Salts; D012680:Sensitivity and Specificity; D012967:Sodium Dodecyl Sulfate
chemical_list: D004655:Emulsions; D036145:Ginsenosides; D012492:Salts; D012967:Sodium Dodecyl Sulfate